Hoping this is the correct forum since some fluoride-sensitive plants are typically grown in containers - is there a more comprehensive plant list available anywhere of fluoride-sensitive plants? I've seen the studies on the 'net that address a handful of plants but wondering if there is a bigger list. I'm on city water and, while I do let the chlorine dissipate before watering plants, I don't think I can do much about the fluoride other than using store-bought water in the winter. Sure explains why my spider plants look awful.
Spider plants are indeed sensitive to compounds of fluorine, but in most cases fluoride takes the rap for spoiled foliage that more rightly belongs at the feet of a soil solution with high EC/TDS (too many dissolved solids/salts) or a soil that remains soggy for too long, impairing root function so plants cannot effectively move water to distal parts, like leaf tips and margins, where damage most often first shows itself. In most cases when it comes to a plant's appearance, the greatest improvement comes from improving root health and root function, which would include a strategy to limit the accumulation of solubles (salts) in the soil solution and minimize the length of time roots are exposed to saturated soil conditions.
Al - thanks for the comments. I did repot them a year ago and haven't used any chemical fertilizers on them. Mainly kelp or fish emulsions. Don't know if there are any salts in those. I do keep them on the dry side, watering maybe once a week but they're not sitting in water. They seem to do better outdoors where they're more likely to get watered with rain water (when I have any in my barrels). Maybe it's the light level? They are in my mini GH where temps don't go below 60 and they do get filtered sun (double glazed poly panels) when the sun is out so not sure if it's a light issue. When they're indoors in the winter, they get city water that's been allowed to sit for at least 48 hours to minimize chlorine.